drm/xe: Stop checking for power_lost on D3Cold

GuC reset status is not reliable for this purpose and it is
once in a while ending up in a situation of D3Cold, where
power_reset is false and without the proper memory restoration
the GuC reload and Display will fail to come back from D3Cold.

So, let's do a full restoration of everything if we have a risk
of losing power, without further optimizations.

v2: also remove the gut_in_reset function (Anshuman)

Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522170105.327472-6-rodrigo.vivi@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_device_types.h

@@ -431,9 +431,6 @@ struct xe_device {
 		/** @d3cold.allowed: Indicates if d3cold is a valid device state */
 		bool allowed;
 
-		/** @d3cold.power_lost: Indicates if card has really lost power. */
-		bool power_lost;
-
 		/**
 		 * @d3cold.vram_threshold:
 		 *

drivers/gpu/drm/xe/xe_guc.c

@@ -1023,30 +1023,3 @@ void xe_guc_print_info(struct xe_guc *guc, struct drm_printer *p)
 	xe_guc_ct_print(&guc->ct, p, false);
 	xe_guc_submit_print(guc, p);
 }
-
-/**
- * xe_guc_in_reset() - Detect if GuC MIA is in reset.
- * @guc: The GuC object
- *
- * This function detects runtime resume from d3cold by leveraging
- * GUC_STATUS, GUC doesn't get reset during d3hot,
- * it strictly to be called from RPM resume handler.
- *
- * Return: true if failed to get forcewake or GuC MIA is in Reset,
- * otherwise false.
- */
-bool xe_guc_in_reset(struct xe_guc *guc)
-{
-	struct xe_gt *gt = guc_to_gt(guc);
-	u32 status;
-	int err;
-
-	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
-	if (err)
-		return true;
-
-	status = xe_mmio_read32(gt, GUC_STATUS);
-	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
-
-	return  status & GS_MIA_IN_RESET;
-}

drivers/gpu/drm/xe/xe_guc.h

@@ -37,7 +37,6 @@ void xe_guc_reset_wait(struct xe_guc *guc);
 void xe_guc_stop_prepare(struct xe_guc *guc);
 void xe_guc_stop(struct xe_guc *guc);
 int xe_guc_start(struct xe_guc *guc);
-bool xe_guc_in_reset(struct xe_guc *guc);
 
 static inline u16 xe_engine_class_to_guc_class(enum xe_engine_class class)
 {

drivers/gpu/drm/xe/xe_pm.c

@@ -404,15 +404,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
 
 	lock_map_acquire(&xe_pm_runtime_lockdep_map);
 
-	/*
-	 * It can be possible that xe has allowed d3cold but other pcie devices
-	 * in gfx card soc would have blocked d3cold, therefore card has not
-	 * really lost power. Detecting primary Gt power is sufficient.
-	 */
-	gt = xe_device_get_gt(xe, 0);
-	xe->d3cold.power_lost = xe_guc_in_reset(&gt->uc.guc);
-
-	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
+	if (xe->d3cold.allowed) {
 		err = xe_pcode_ready(xe, true);
 		if (err)
 			goto out;
@@ -433,7 +425,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
 	for_each_gt(gt, xe, id)
 		xe_gt_resume(gt);
 
-	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
+	if (xe->d3cold.allowed) {
 		xe_display_pm_resume(xe, true);
 		err = xe_bo_restore_user(xe);
 		if (err)